Me too. But I have other slides from the same time that still show superb, natural colors. When I brought them to editing, I couldn’t find anything left to do regarding tone mapping. My brother raised a question whether chemicals could react differently depending on the exposure values, for example, under exposed images would degrade faster and maybe present some color cast even from the beginning. Who knows.
Look at this one, from the same time:
EDIT: The Zeiss Contaflex that shot the girls picture is with the third guy from right, who happens to be my father.